Sullair LS-12 Operators Manual And Parts Lists page 12

Figure 2 ---3 Compressor Fluid Cooling and Lubrication System
connecting piping and tubing. For water---cooled
models, two shell and tube heat exchangers and a
water---flow regulating valve are substituted for the
radiator---type coolers listed above.
The pressure in the receiver/sump causes fluid flow
by forcing the fluid from the high pressure area of
the sump to an area of lower pressure in the com-
pressor unit.
Fluid flows from the bottom of the receiver/sump to
the thermal valve. The thermal valve is fully open
when the fluid temperature is below 170_F (77_C).
The fluid passes through the thermal valve, the
main filter and directly to the compressor unit
where it lubricates, cools and seals the rotors and
the compression chamber.
As the discharge temperature rises above 170_F
(77_C), due to the heat of compression, the ther-
DESCRIPTION
mal valve begins to close and a portion of the fluid
then flows through the cooler. From the cooler the
fluid flows to the main filter and then on to the com-
pressor unit.
A portion of the fluid flowing to the compressor is
routed to the anti---friction bearings which support
the rotors inside the compressor unit. Prior to enter-
ing the compressor unit, this fluid is taken through
the fluid filter, thus assuring properly filtered lubri-
cant for bearing supply.
The fluid filter has a replacement element and an in-
tegral pressure bypass valve. A gauge on the in-
strument panel shows red when the filter needs
servicing. This gauge has a pressure setting lower
than that of the bypass valve. After the initial 50
hour filter change, the gauge will rarely show red
under normal operating conditions.
The fluid stop valve prevents fluid from filling the
Section 2
7